Let's think about the conflicts I mentioned in my entry "Flow of Structured Information".
First let's accept this: only conflict is interesting. A long description of the mountains can be nice, but can't be really cool, unless there is some counterpoint to it. This is what I initially called conflict, because I was thinking about how the GM should "tell the story", but it is true that this truth can be extended to PCs, etc.
Let's look at what conflicts there can be. There are informations submitted by the GM and by the players, so conflicts can be between
- GM-GM
- same player
- different player
- player-GM
informations.
GM-GM conflict is one of the most important conflicts. It does not mean that the GM is in conflict with him/herself, but that there is a conflict between 2 of the informations submitted by the GM. The first information is the baseline, the second is the counterpoint. (But they are each others counterpoint!) You can always reinforce it with a third information: being the 1st the baseline, the 2nd makes it a pattern and the 3rd will be a counterpoint.
It is very important that you use patterns if the players are new to the presented baseline information. (For example if the players are new to the setting, you should use the element introduced as normal in the world at least twice before complicating things.)
If this thing is known to the players or trivial, you shouldn't use the third, reinforcement, because it can get boring if you don't introduce more conflicts. (For example the PCs have a good time at an inn before daring into the sulphuric dens of a dragon. But if they are guests to two inns and have a good time, that means they have a very good life as adventurers wich mostly isn't true.) You can deepen the conflict by moving the two counterpoints closer to each other. (For example somehow remembering the players to the baseline.)
Don't forget, that these conflicts can work on different levels, and it should, or it will become boring: there can be a high level conflict in the adventure, like the inn-vs-denn and there can be a conflict in the inn, like a dancer who entertains the party, but has a sad past, etc.
You can make really a lot of conflicts without confusing the players if those conflicts are structured. (For example by a common cause or a common thematic.) Works regarding art and fictionwriting can help in this, but never forget, that the actual play won't be carved in stone, so you don't have to bother how it will look afterwards. Not the structure of the story is important, but what the players experience. You have to depend on that you are face to face with the players: you don't have to use more tricks, after you see that the players "get it". It is a very important, but - as I see it - overlooked fact. Don't stick to the planned tricks, but stick to the planned effects you want to achieve in the players.
If the same player tells two informations that are conflicting is similar to the GM-GM conflict in many regards. The important difference is, that the player has only limited influence on the in-game facts. That is: the player can do this only by making decisions that matter. An important baseline information can be the description of the character, and the character sheet itself. The character sheet is part of the game, you shouldn't forget this. It is a common trick in fiction, that the first time you see a character, (s)he is acting very unusually and this is stated by other characters. So, the character sheet is the baseline and a simple conflict can be made by not acting as the character sheet would implicate it.
Of course, randomness is even more unwanted in the behavior of characters - an advice to players: the more you stick to a baseline, the bigger the wham will be of the change. For example if you are playing a pedant jovial burger of a city, and after ten sessions something happens to you and this is the first instance that you will use a hard word, it will be much more effective than swearing all the time.
Of course there are changes on the character sheet, so you can always confront with these changes. For example: how would your character react to gaining a level?
This is where player-GM conflict comes into the view. This part is where the player gives an information that conflicts with the GM's information. Note, that this doesn't mean that the player is disregarding GM fiat. In opposite: this means that the player not only accepts a GM information, but reacts to that. Because the GM is an alien lifeform, the player mostly won't be able to answer the GM in the way the GM intended. This means always conflict.
If the player wants to make a pattern of the baseline info submitted by the GM (note: a baseline information can be the counterpoint of another baselint information), it will be only in the sense of the player a pattern, all the other players and the GM will see some minor (or major) conflict. The cause of this, that there is always some conflict between every information, but the accentation defines wich parts of the information should be regarded. (For example if in the above mentioned inn the player wants to have fun with the dancer, because wants to make a pattern of the dancer entertaining them, it can become a conflict, because it is not permitted to touch the dancers of the inn, or the dancer don't wants it at all because her sad past, etc.)
The other kind of player-GM conflict is when the player wants a conflict against a GM information. This is mostly obvious, because it is very showy. The player mostly sais "no" to something. (In wich the information isn't disregarded, but the player acts against it.) Certainly it can be subtle, in wich case it can be seen incidentally as pattern. In this case the player mostly makes it a conflict with the next info.
You can't talk about player-GM conflict without GM-player conflict. It is the most important conflict in GMing. The GM reacts to the decisions of the players: that is the definition of storytelling. (Although it has almost nothing to do with telling a story.)
Well, this is the fine art of GMing. Should I mess with the PC or let the player think that (s)he can be successful? It's almost like being an archenemy wich is that evil that lets the PCs succeed only to suffer longer. I really can't give advices in this, because whole RPGs are about this. I can only analyze its structure.
GM reaction to player informations are always instant. The GM has to permit, modify or ban the information given by a player. Permission is easy, but the GM can always make it a modification to get more interesting. Ban is sometimes needed, but if it can be made into a modification, it will become more exciting.
The interesting thing in modifying the information given by the player is that you can make simple decisions into decisions that matter. (For example: Player: I want to assemble a team for a quest into the mountains. GM: Okay, but the only person you know is able to assemble such a team is your former love's fiancee.) The important part of this, that you have to prompt questions: you have to have informations about the PCs given by the players. This requires background story, description of personality, etc. If you only do a dungeoncrawl and the decisions only matter if they are about the survival, you don't need background story for the PCs. (I personnaly didn't require bg-story from the players, because they didn't know the setting. I'm letting them conceptualize their characters by telling stories by the side of campfire.)
The conflict between informations given by different players is one of the most interesting and exciting conflicts. There are times when the GM can sit back and enjoy the view, but sometimes there are need to stop an ensuing mortal kombat before it comes to a finish him/her. (Yes, combat can be seen as conflict, too, but I think it's not as interesting, because that is covered by the rules.)
Conflicts between different players is interesting, because the two players give the two counterpoints of the conflict, and the GM has the possibility of trying to make a pattern or enter another (second and third) conflict into the picture. The problem is: all the three partakers have a different view on informations, wich means it is possible that players won't even notice if there is a conflict between them wich can be seen by the GM (or other players! OMG) or that the players see a conflict between each other wich the GM doesn't see. These threesomes are one of the most delicate instances of the game. It is not even covered in most rules. (Never forget, that the combat rules aren't intended to be between PCs, but between PC and monster/NPC. That is, the combat values of a PC don't really tell anything what the character is able to do with another PC. It's only a historical coincidence that the values used against PCs and against NPCs have the same name. It won't have to be like that. For example a PC can have different "THAC0"-s for different weapons, but because a monster can't change weapons, it needs only one "attack value". These are not the same.)
Note: this was only a list of possible conflicts. It's not that exhaustive as I intended or it should be. Each and every type of conflict should have a whole own chapter how to handle them.